A modem is a conversion interface that enables digital data being transmitted on an analog signal transmission line. A mobile communication modem is a part of a mobile communication device such as a mobile phone or a data card. A mobile communication modem device is a device that includes a mobile communication modem, examples of which include mobile phones, mobile broadband data cards, and tablet computers equipped with third generation (3G) communication capabilities.
Conventionally, a mobile communication modem or a mobile communication modem device (collectively referred to as “modem” hereinafter) is capable of searching for a network in a standby state. In network searching strategies, an S criterion and an R criterion are used. The S criterion is used to control a start strategy, whereas the R criterion is used to filter a neighboring cell, so as to switch a serving cell from a current serving cell to a filtered neighboring cell. In applying the S criterion, the signal quality and signal power of a current serving cell where the modem camps on need to be detected in order to obtain a signal quality factor and a signal power factor of the serving cell. A filtering is started when either of the two reaches a threshold value. The R criterion may be used in the filtering, and with the R criterion applied, a neighboring cell is selected according to measured signal quality values of a plurality of neighboring cells. In order to obtain a neighboring cell through reselection immediately when signal strength of the serving cell declines, related operations such as signal quality measurement and signal power measurement need to be performed on the serving cell and the neighboring cells at the same time. Herein, a serving cell refers to a cell with which a modem is having a connection with, and user information is sent from the cell. Neighboring cells refer to two cells with overlapping coverage and between which a switching relationship exists. One cell may have a plurality of neighboring cells. Network search means to search for a mobile communication network according to strength and quality of wireless signals.
However, in the existing technology, a data source for applying the S criterion thereon is an instantaneous value of a network signal, and momentary signal weakening caused by network signal fluctuation, which does not affect normal standby of a modem, would affect a calculation result using the S criterion. Once the calculation result reaches a threshold value, a network search measurement is started. In the network search measurement, searching for a neighboring cell needs to be performed, and much electricity is consumed during the search for the neighboring cell. Especially, in the case of many neighboring cells, workload of the modem is greatly increased.